Institute of Cell Biology, University of Bern, Switzerland.
Curr Genet. 2010 Jun;56(3):237-49. doi: 10.1007/s00294-010-0296-0. Epub 2010 Apr 3.
DNA double-strand breaks (DSBs) initiate meiotic recombination in Schizosaccharomyces pombe and in other organisms. The Rec12 protein catalyzes the formation of these DSBs in concert with a multitude of accessory proteins the role of which in this process remains to be discovered. In an all-to-all yeast two-hybrid matrix analysis, we discovered new interactions among putative members of the meiotic recombination initiation complex. We found that Rec7, an axial-element associated protein with homologies to Saccharomyces cerevisiae Rec114, is interacting with Rec24. Rec7 and Rec24 also co-immunoprecipitate in S. pombe during meiosis. An amino acid change in a conserved, C-terminal phenylalanine in Rec7, F325A interrupts the interaction with Rec24. Moreover, rec7F325A shows a recombination deficiency comparable to rec7Delta. Another interaction was detected between Rec12 and Rec14, the orthologs of which in S. cerevisiae Spo11 and Ski8 interact accordingly. Amino acid changes Rec12Q308A and Rec12R309A disrupt the interaction with Rec14, like the according amino acid changes Spo11Q376A and Spo11RE377AA loose the interaction with Ski8. Both amino acid changes in Rec12 reveal a recombination deficient rec12 (-) phenotype. We propose that both Rec7-Rec24 and Rec12-Rec14 form subcomplexes of the meiotic recombination initiation complex.
DNA 双链断裂（DSBs）在裂殖酵母和其他生物中引发减数分裂重组。Rec12 蛋白与多种辅助蛋白协同催化这些 DSB 的形成，而这些辅助蛋白在这个过程中的作用尚待发现。在全对全酵母双杂交矩阵分析中，我们发现了减数分裂起始复合物的假定成员之间的新相互作用。我们发现，Rec7 是一种与酿酒酵母 Rec114 同源的轴体相关蛋白，与 Rec24 相互作用。Rec7 和 Rec24 在裂殖酵母减数分裂过程中也共同免疫沉淀。Rec7 中保守的 C 末端苯丙氨酸的氨基酸改变，F325A 中断了与 Rec24 的相互作用。此外，rec7F325A 显示出与 rec7Delta 相当的重组缺陷。还检测到 Rec12 和 Rec14 之间的另一个相互作用，酿酒酵母 Spo11 和 Ski8 的同源物相应地相互作用。氨基酸变化 Rec12Q308A 和 Rec12R309A 破坏了与 Rec14 的相互作用，就像相应的氨基酸变化 Spo11Q376A 和 Spo11RE377AA 与 Ski8 的相互作用一样。Rec12 中的两种氨基酸变化都显示出重组缺陷的 rec12（-）表型。我们提出 Rec7-Rec24 和 Rec12-Rec14 都形成了减数分裂起始复合物的亚复合物。
